Krypton

Koushik 26/06/2026 19:58:08 Updated 26/06/2026 19:58:08

Property	Value
Atomic Number	36
Element	Krypton
Symbol	Kr
Atomic Mass	83.798 u
Number of Neutrons	48 (most common isotope, Krypton-84)
Number of Protons	36
Number of Electrons	36
Period	4
Group	18
Phase	Gas
Radioactive	No
Natural	Yes
Metal	No
Nonmetal	Yes
Metalloid	No
Type	Noble Gas
Atomic Radius	88 pm
Electronegativity	3.00 (Pauling scale)
First Ionization Energy	13.999 eV
Density	0.003733 g/cm³
Melting Point	−157.36 °C
Boiling Point	−153.22 °C
Number of Isotopes	6 stable (Kr-78, Kr-80, Kr-82, Kr-83, Kr-84, Kr-86)
Discoverer	William Ramsay, Morris Travers
Year	1898
Specific Heat	0.248 J/g·K
Number of Shells	4
Number of Valence Electrons	8